1. Field of the Invention
The present invention relates to an optical fiber recoating device for reapplying a resin coating to areas along an optical fiber where a sheath has been removed. More specifically, the present invention relates to a design which reduces the cost of the device and which promotes resin curing.
2. Description of the Related Art
When connecting optical fibers using heat fusion, or after removing damaged areas of a sheath of the optical fiber, it is necessary to reapply resin to these areas (i.e., to the bare fiber areas) in order to protect the optical fiber. In other words, the optical fiber must be recoated.
A number of devices have been proposed as conventional recoating devices. One example of these is a device such as shown in FIGS. 9 and 10 which is of a type (mold type) in which recoating is performed by filling recoating resin into a mold made of glass.
This recoating device 10 has upper and lower molds 11A and 11B which are typically made of a material such as quartz glass which has excellent light transmitting properties. These molds 11A, 11B are provided between a base 12 and a lid 13 which is attached to the base 12 so as to enable opening and closing thereof. The recoating resin (typically a UV curable resin) is filled into the respective semicircular mold grooves 16 of the molds 11A, 11B via resin filling routes 14, 15 which are formed in the lid 13 and upper mold 11B, for example.
As shown in FIG. 11, for example, the length of each mold groove 16 is designed to be longer than a bare fiber part 1a of an optical fiber 1 which is provided by connecting two optical fibers using heat fusion.
When this optical fiber 1 is set in place in respective mold grooves 16 of the molds 11A, 11B, a nearly closed cylindrical space (mold space) is formed inside the mold grooves 16 at the bare fiber part 1a. The recoating resin is then filled into the space, and a recoated sheath 2, i.e., a molded portion, is formed.
Furthermore, when a resin curing lamp 17, such as a UV lamp, is provided on the base 12 side for example, and UV light is radiated at this time, curing of the resin can be promoted and the rapid recoating can be performed.
Increasing the number of resin curing lamps might be considered in order to carry out this resin curing more effectively. However, securing adequate space for the lamps is difficult since a viewing window 11 is typically provided on the lid 13 side which opens in the direction of the upper mold 11B and is for observing the inflow of the recoating resin.
Moreover, when the number of lamps is increased, then the device of course becomes more complicated with the inclusion of these parts, and costs increase.
In addition, as shown in FIGS. 12 and 13, in the above-described recoating device 10, the recoating resin leaks out between the abutting surfaces of the molds 11A, 11B, as well as into the space in between the mold grooves 16 and a sheath 1b of the optical fiber 1. Once hardened, this resin forms thin resin pieces what are called burrs 2a, 2b. 
For this reason, as shown in FIG. 14, a method has been proposed for providing a light blocking layer 19, such as a metal layer, on the abutting surfaces of the molds 11A, 11B in some devices. However, in this design, the light from the resin curing lamp 17 on the base 12 side can hardly reach the mold 11B on the opposite side. Thus, this is problematic since one resin curing lamp is not sufficient.